A method for detecting the grouting fullness of a grouting sleeve

Abstract

The present invention discloses a method for detecting the grouting fullness of grouting sleeves, which includes: preparing a standard grouting fluid, performing neutron detection on each detection point of grouted and ungrouted sleeves one by one, and taking the detection results as a reference standard neutron number library; before grouting the sleeves in the component, performing neutron detection, and taking the measured neutron quantity as the background value; grouting the sleeves in the component with the prepared standard grouting fluid, performing neutron detection on each detection point one by one, and the measured neutron number is the neutron number with the background value; subtracting the neutron number with the background value from the background value to obtain the actually measured neutron number of the sleeves in the component; comparing and analyzing the actually measured neutron number of the sleeves in the component with the reference standard neutron number to finally obtain the detection result. According to the grouting situation, the final detection result can be divided into three levels: ungrouted, insufficient grouting, and full grouting; insufficient grouting is further divided into air-filled pores and water-filled pores. The present invention makes full use of the characteristic that neutrons can penetrate metal, and realizes the detection of the grouting fullness of grouting sleeves.

Description

Technical Field

[0001] The present invention relates to the technical field of neutron non-destructive testing, and particularly to a method for detecting the grouting fullness of a grouting sleeve. Background Art

[0002] There are more and more prefabricated buildings. Among them, the connection of components in prefabricated buildings is a weak link in prefabricated buildings. Grouting sleeve connection accounts for a relatively large proportion in prefabricated buildings. However, the grouting fullness of the sleeve is related to the safety of the structure. Therefore, solving the problem of grouting sleeve detection is crucial for the development of prefabricated buildings.

[0003] At present, there are many methods for detecting the grouting fullness of sleeves in China, mainly including direct methods and indirect methods. Among them, the direct methods include the embedded wire drawing method and the endoscope method. The accuracy of both methods can meet the requirements, but it is necessary to embed wires and reserve holes. The indirect methods include the ground penetrating radar method, the impact echo method, the ultrasonic method, the X-ray method, etc. The ground penetrating radar method is good at detecting defects in concrete. However, since the sleeve is made of thick steel, it has a shielding effect on electromagnetic waves, and the signal of the ground penetrating radar cannot enter the inside of the sleeve. The ultrasonic method and the impact echo method are easily affected by the external environment. At the same time, the steel plate is a high-speed layer. When relying on the reflection method, it has to pass through the high-speed layer twice, and the energy attenuation of the wave is relatively serious. The X-ray can better detect the grouting fullness of the sleeve, but the penetration depth of this method is limited. Therefore, there is an urgent need for a more effective method for detecting the grouting fullness of grouting sleeves. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for detecting the grouting fullness of a grouting sleeve, so as to solve the problems existing in the above-mentioned prior art, and make the operation simple and the detection accuracy improved.

[0005] To achieve the above purpose, the present invention provides the following scheme:

[0006] The present invention provides a method for detecting the grouting fullness of a grouting sleeve, which specifically includes the following steps:

[0007] Step 1, make a detection template with the positions of detection points according to the sleeve specifications. Use two sleeves, install the detection templates on the two sleeves respectively. Fill one sleeve with standard grout, and leave the other sleeve ungrouted. Conduct neutron detection one by one according to the arrangement order of the detection points, and use the detection results as the reference standard neutron number library of the grouted and ungrouted sleeves;

[0008] Step 2, select two identical component inner sleeves and install the detection templates respectively, one of the component inner sleeves is not grouted, and neutron detection is performed one by one according to the arrangement order of the detection points, and the measured number of neutrons is used as the background value; the other component inner sleeve is filled with standard grouting, and neutron detection is performed one by one according to the arrangement order of the detection points, and the measured number of neutrons is used as the background value, and the background value is subtracted from the background value to obtain the measured neutron number of the component inner sleeve.

[0009] Step three, comparing and analyzing the measured neutron number of the sleeve inside the component with the neutron number in the reference standard neutron number library, and finally obtaining the test results, which include no grouting, incomplete grouting and full grouting. Incomplete grouting includes pores filled with air and filled with water.

[0010] Preferably, in step 2, the position of the sleeve inside the component needs to be determined first. For a single grouting sleeve, the position of the sleeve on the component surface is determined based on the grouting inlet and outlet of the sleeve; for a connected sleeve grouting, the position of the sleeve on the component surface is determined using the outlet and ground penetrating radar scanning.

[0011] Preferably, a set of the detection templates is made for each specification of sleeve, and the detection templates can be mounted on the slurry inlet and the slurry outlet of the sleeve for use. Each sleeve detection requires at least two sets of detection components, and the detection components include mutually matching neutron sources and receiving probes. The detection template is evenly distributed with at least two columns of detection frames along the length direction of the sleeve, and each of the detection frames can be clamped with the detection components, the slurry inlet and the slurry outlet, and each of the detection frames corresponds to one detection point.

[0012] Preferably, three rows of detection frames are evenly distributed on the detection template along the length direction of the sleeve, and the cross-sections of the three detection frames in the same row are trapezoidal and are all arranged along the radial direction of the sleeve.

[0013] Preferably, before grouting in step 2, the detection assembly is moved sequentially to the detection point positions on the detection template, each detection point is measured for 1 minute, and three receiving probes obtain three thermal neutron numbers as the initial background value of the detection point until the detection of all detection points is completed.

[0014] Preferably, the detection assembly is sealed in a rectangular box, the rectangular box can be movably snap-fitted into the detection frame, and the neutron source emits neutrons radially along the sleeve.

[0015] Preferably, for determining the receiving time of the receiving probe, the principle of neutron emission by the neutron source and thermal neutron reception by the receiving probe is used to detect the ungrouted sleeve and the grout-filled sleeve in the component on the surface of the component for different times. The time when there is an obvious difference in the number of neutrons detected in the ungrouted sleeve and the grout-filled sleeve is determined as the receiving time.

[0016] Preferably, for estimating the detection depth, based on the water content of the grout in the grouting sleeve and the water content in the concrete, the burial depth of the grouting sleeve in the concrete that can be detected by the neutron scattering method is estimated.

[0017] Preferably, the measured number of neutrons in the sleeve in the component is compared and analyzed with the reference standard neutron number library. When the measured number of neutrons in the sleeve in the component is similar to the number of neutrons measured in the grout-filled sleeve, it indicates that the sleeve is grout-filled; when the measured number of neutrons in the sleeve in the component is similar to the number of neutrons measured in the ungrouted sleeve, it indicates that the sleeve is not grouted.

[0018] Preferably, when there is a large difference between the measured number of neutrons in the sleeve in the component and the number of neutrons measured at some detection points of the grout-filled sleeve, it indicates that the grouting is not full near this detection point. If the detected value at this detection point is significantly greater than the neutron value of the grout-filled sleeve, it indicates that there is water filling near this detection point; if the value at this detection point is significantly less than the neutron value of the grout-filled sleeve, it indicates that there is air filling near this detection point.

[0019] The present invention has achieved the following technical effects compared with the prior art:

[0020] The present invention makes full use of the characteristic that neutrons can penetrate metals, realizes the detection of the grouting fullness of the grouting sleeve, and makes the operation simple and the detection accuracy improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the following described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 It is a schematic diagram of the principle of the method for detecting the grouting fullness of the grouting sleeve of the present invention;

[0023] Figure 2 It is a schematic structural diagram of the detection template in the present invention;

[0024] Figure 3 It is a schematic structural diagram of the detection component in the present invention;

[0025] Wherein: 1 - sleeve, 2 - detection point, 3 - detection template, 4 - neutron source, 5 - receiving probe. Specific implementation mode

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0027] The purpose of the present invention is to provide a method for detecting the grouting fullness of a grouting sleeve to solve the problems existing in the prior art and make the operation simple and the detection accuracy improved.

[0028] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation modes.

[0029] As Figures 1 to 3 shown: This embodiment provides a method for detecting the grouting fullness of a grouting sleeve, which specifically includes the following steps:

[0030] Step 1, make a detection template with the positions of detection points according to the sleeve specifications. Use two sleeves, install the detection templates on the two sleeves respectively. Fill one sleeve with standard grout, and leave the other sleeve ungrouted. Perform neutron detection one by one according to the arrangement order of the detection points, and use the detection results as the reference standard neutron number library for the grouted full and ungrouted sleeves. Respectively use the neutron scattering method to measure the number of thermal neutrons in a certain time in each state, and use this as the detection standard.

[0031] Step 2, select the inner sleeves of two identical components and install the detection templates respectively. Leave the inner sleeve of one component ungrouted, and perform neutron detection point by point according to the arrangement order of the detection points. Use the measured neutron quantity as the background value. Fill the inner sleeve of the other component with standard grout, and perform neutron detection one by one according to the arrangement order of the detection points. Use the measured neutron number with the background value. Subtract the background value from the measured neutron number with the background value to obtain the measured neutron number of the inner sleeve of the component. In step 2, it is necessary to first determine the position of the inner sleeve of the component. For a single grouting sleeve, determine the position of the sleeve on the surface of the component according to the grouting inlet and outlet of the sleeve (the connection line between the inlet and outlet is the position of the sleeve); for the grouting of connected sleeves, use the outlet and ground penetrating radar scanning to determine the position of the sleeve on the surface of the component.

[0032] Before grouting in Step 2, move the detection component successively to the positions of the detection points on the detection template. Measure each detection point for 1 minute. Three receiving probes obtain three thermal neutron counts, which are used as the initial background value of this detection point until the detection of all detection points is completed. This initial background value reflects the result of fast neutron moderation within a certain volume between the neutron source and the receiving probes, so that the thermal neutron background count reflecting the entire sleeve can be obtained on the concrete surface. The detection component is sealed in a rectangular box. The neutron emission area of the neutron source for neutron detection is rectangular, and other areas are shielded. The rectangular box can be movably clamped in the detection frame, and the neutron source emits neutrons along the radial direction of the sleeve, so that the thermal neutrons collected by the receiving probes are mainly moderated by the hydrogen atoms in the grouting material within the grouting sleeve, preventing the spherical uniform distribution of neutrons and excessive neutrons from the surrounding concrete from entering the receiving probes, thereby improving the detection accuracy.

[0033] To determine the receiving time of the receiving probes, use the principle that the neutron source emits neutrons and the receiving probes receive thermal neutrons to detect the components with ungrouted sleeves and fully grouted sleeves within the component surface at different times. When there is an obvious difference in the neutron counts detected for the ungrouted sleeve and the fully grouted sleeve, that time is determined as the receiving time.

[0034] In Step 3, compare and analyze the measured neutron count of the sleeve within the component with the neutron counts in the reference standard neutron count library, and finally obtain the detection result. The detection results include ungrouted, insufficiently grouted, and fully grouted. Insufficiently grouted includes pores filled with air and filled with water. Compare and analyze the measured neutron count of the sleeve within the component with the reference standard neutron count library. When the measured neutron count of the sleeve within the component is approximately the same as the neutron count measured for the fully grouted sleeve, it indicates that the sleeve is fully grouted; when the measured neutron count of the sleeve within the component is approximately the same as the neutron count measured for the ungrouted sleeve, it indicates that the sleeve is ungrouted. When there is a large difference between the measured neutron count of the sleeve within the component and the neutron counts measured at some detection points of the fully grouted sleeve, it indicates that the grouting is insufficient near this detection point. If the detected value at this detection point is significantly greater than the neutron value of the fully grouted sleeve, it indicates that there is water filling near this detection point; if the value at this detection point is significantly less than the neutron value of the fully grouted sleeve, it indicates that there is air filling near this detection point.

[0035] Make a set of detection templates for each specification of the sleeve. The detection templates can be sleeved on the slurry inlet and outlet of the sleeve for use. At least two sets of detection components are required for each sleeve detection. The detection components include mutually matching detection components. There are at least two columns of detection frames evenly distributed along the length direction of the sleeve on the detection template. Each detection frame can be clamped with the detection components, the slurry inlet and the slurry outlet, and each detection frame corresponds to a detection point. There are three columns of detection frames evenly distributed along the length direction of the sleeve on the detection template. The cross-sections of the three detection frames in the same row are trapezoidal and are all arranged radially along the sleeve, and three groups of data can be detected. The data are compared with each other to further confirm the detection result. The receiving probe can be a helium-3 proportional counter or a enriched BF3 counter, which is small in volume and has a high detection efficiency and is suitable for various diameters of grouting sleeves.

[0036] The detection principle of this embodiment is as follows: Assume that the water contained in the sleeve after grouting solidifies is evenly distributed. There are obvious differences in the water content in the three states of the sleeve being fully grouted, not grouted, and underfilled grouting (filled with gas or water). This is the physical basis for being able to detect the grouting fullness using neutron scattering technology. The neutron source emits fast neutrons. The fast neutrons collide with the hydrogen nuclei. After the collision, the energy of the neutrons decreases. When the neutrons become thermal neutrons (0.025ev) after the collision, they diffuse in the concrete. A part of the thermal neutrons reach the surface of the reinforced concrete and are received by the receiving probe. The number of thermal neutrons received at this point reflects the water content of the detection component in a certain volume of concrete. Since the water content in the grouting solid is uniform, the water content can reflect the saturation of the grouting. This embodiment makes full use of the characteristic that neutrons can penetrate metals, realizes the detection of the grouting fullness of the grouting sleeve, and makes the operation simple and the detection accuracy improved.

[0037] In this specification, specific examples are used to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for detecting the grouting fullness of a grouting sleeve, characterized in that: Specifically, it includes the following steps: Step 1: Make a detection template with the positions of detection points according to the sleeve specifications. Use two sleeves, install the detection templates on the two sleeves respectively. Fill one sleeve with standard grout, and leave the other sleeve unfilled. Conduct neutron detection one by one according to the arrangement order of the detection points, and use the detection results as the reference standard neutron number library for the grout-filled and unfilled sleeves; Step 2: Select two identical inner sleeves of components and install the detection templates respectively. Leave one inner sleeve of the component unfilled, conduct neutron detection one by one according to the arrangement order of the detection points, and use the measured neutron quantity as the background value. Fill the other inner sleeve of the component with standard grout, conduct neutron detection one by one according to the arrangement order of the detection points, and use the measured neutron number with the background value. Subtract the background value from the measured neutron number with the background value to obtain the measured neutron number of the inner sleeve of the component; Step 3: Compare and analyze the measured neutron number of the inner sleeve of the component with the neutron numbers in the reference standard neutron number library to finally obtain the detection result. The detection result includes unfilled, insufficient grouting, and full grouting. The insufficient grouting includes air-filled pores and water-filled pores; Make one set of the detection template for each specification of the sleeve. The detection template can be sleeved on the grout inlet and outlet of the sleeve for use. At least two sets of detection components are required for the detection of each sleeve. The detection component includes a neutron source and a receiving probe that match each other. At least two columns of detection frames are evenly distributed along the length direction of the sleeve on the detection template. Each detection frame can be clamped with the detection component, the grout inlet, and the grout outlet. Each detection frame corresponds to one detection point; Three columns of detection frames are evenly distributed along the length direction of the sleeve on the detection template. The cross-sections of the three detection frames in the same row are trapezoidal and are all arranged radially along the sleeve; Compare and analyze the measured neutron number of the inner sleeve of the component with the reference standard neutron number library. When the measured neutron number of the inner sleeve of the component is similar to the neutron number measured by the full-grout sleeve, it indicates that the sleeve is fully grouted; When the measured neutron number of the inner sleeve of the component is similar to the neutron number measured by the unfilled sleeve, it indicates that the sleeve is unfilled; When the difference between the measured neutron number of the inner sleeve of the component and the neutron numbers of some detection points of the full-grout sleeve is large, it indicates that the grouting near this detection point is insufficient. If the detection value of this detection point is significantly greater than the neutron value of the full-grout sleeve, it indicates that there is water filling near this detection point; If the value of this detection point is significantly less than the neutron value of the full-grout sleeve, it indicates that there is air filling near this detection point.

2. The method for detecting the grouting fullness of the grouting sleeve according to claim 1, wherein: In Step 2, it is necessary to first determine the position of the inner sleeve of the component. For a single grout sleeve, determine the position of the sleeve on the surface of the component according to the grout inlet and outlet of the sleeve; For the grouting of connected sleeves, use the grout outlet and ground penetrating radar scanning to determine the position of the sleeve on the surface of the component.

3. The method for detecting the grouting fullness of a grouting sleeve according to claim 1, characterized in that: Before grouting in the second step, move the detection component sequentially to the positions of the detection points on the detection template. Measure for 1 minute at each detection point. Three thermal neutron counts are obtained by the three receiving probes, which serve as the initial background value for this detection point until the detection of all detection points is completed.

4. The method for detecting the grouting fullness of a grouting sleeve according to claim 1, wherein: The detection component is sealed in a rectangular box, which can be movably clamped in the detection frame, and the neutron source emits neutrons along the radial direction of the sleeve.

5. The method for detecting the grouting fullness of the grouting sleeve according to claim 1, wherein: To determine the receiving time of the receiving probe, the principles of neutron source emitting neutrons and receiving probe receiving thermal neutrons are used to detect the ungrouted sleeve and the fully grouted sleeve in the component on the surface of the component for different times. The time when there is an obvious difference in the neutron counts of the ungrouted sleeve and the fully grouted sleeve is the determined receiving time.

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